3x^2-42x+40=0

Simple and best practice solution for 3x^2-42x+40=0 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for 3x^2-42x+40=0 equation:


Simplifying
3x2 + -42x + 40 = 0

Reorder the terms:
40 + -42x + 3x2 = 0

Solving
40 + -42x + 3x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
3 the coefficient of the squared term: 

Divide each side by '3'.
13.33333333 + -14x + x2 = 0

Move the constant term to the right:

Add '-13.33333333' to each side of the equation.
13.33333333 + -14x + -13.33333333 + x2 = 0 + -13.33333333

Reorder the terms:
13.33333333 + -13.33333333 + -14x + x2 = 0 + -13.33333333

Combine like terms: 13.33333333 + -13.33333333 = 0.00000000
0.00000000 + -14x + x2 = 0 + -13.33333333
-14x + x2 = 0 + -13.33333333

Combine like terms: 0 + -13.33333333 = -13.33333333
-14x + x2 = -13.33333333

The x term is -14x.  Take half its coefficient (-7).
Square it (49) and add it to both sides.

Add '49' to each side of the equation.
-14x + 49 + x2 = -13.33333333 + 49

Reorder the terms:
49 + -14x + x2 = -13.33333333 + 49

Combine like terms: -13.33333333 + 49 = 35.66666667
49 + -14x + x2 = 35.66666667

Factor a perfect square on the left side:
(x + -7)(x + -7) = 35.66666667

Calculate the square root of the right side: 5.972157623

Break this problem into two subproblems by setting 
(x + -7) equal to 5.972157623 and -5.972157623.

Subproblem 1

x + -7 = 5.972157623 Simplifying x + -7 = 5.972157623 Reorder the terms: -7 + x = 5.972157623 Solving -7 + x = 5.972157623 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '7' to each side of the equation. -7 + 7 + x = 5.972157623 + 7 Combine like terms: -7 + 7 = 0 0 + x = 5.972157623 + 7 x = 5.972157623 + 7 Combine like terms: 5.972157623 + 7 = 12.972157623 x = 12.972157623 Simplifying x = 12.972157623

Subproblem 2

x + -7 = -5.972157623 Simplifying x + -7 = -5.972157623 Reorder the terms: -7 + x = -5.972157623 Solving -7 + x = -5.972157623 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '7' to each side of the equation. -7 + 7 + x = -5.972157623 + 7 Combine like terms: -7 + 7 = 0 0 + x = -5.972157623 + 7 x = -5.972157623 + 7 Combine like terms: -5.972157623 + 7 = 1.027842377 x = 1.027842377 Simplifying x = 1.027842377

Solution

The solution to the problem is based on the solutions from the subproblems. x = {12.972157623, 1.027842377}

See similar equations:

| 4x^3+6x^2+2x-3=0 | | 14x-(6x-5)=45 | | 6(m-1)=-6+8m | | 15x^3+17x^2-4x=0 | | 5x+17-3x=8+4x-5 | | 11x+7=4(x-7) | | -38+8k=8(k-5) | | 11+7=4(x-7) | | 0.8+x=x+1.16 | | 6x+7=3x+52 | | -3(-9v+3)-3v=6(v-2)-5 | | 4x-7(3)=5x+14 | | 2(x-3)=3(x+2) | | (w^2-5w-6)+(3w^2-4w+2)=0 | | 2-2x=-2(x-1) | | 2+2x=-14 | | 11-18x-8x^2=0 | | x^3-225x=0 | | x+2+4+3=1-x | | 3y+8=2y-1 | | 9x-12=-6 | | 12+1+4m+6m=1+4m | | -19-6z=-7(4z-8) | | 3x^3+18x^2+18= | | -4p+10=4-5p | | 9x^4=37x^2-4 | | 13-44=3(x-5)-7 | | 3*x+7=17 | | 2y-6=-20 | | 7a-2=2(a+9) | | 289*5= | | 3x+15=-30 |

Equations solver categories